1. Technical Field
This invention relates generally to in-vehicle navigation systems and, in particular, to a method and system for displaying visual images on a portable computing device to assist a user in locating traffic landmarks.
2. Description of the Related Art
Recently, the computer industry has sought to add computer processing and communications capabilities to devices other than what would normally be considered a traditional computer. Such devices are quite varied and include, for example, personal digital assistants (PDAs), smartphones, cellular phones, desktop screen phones, in-vehicle devices, vehicle traffic lights, kiosks, business organizers (e.g., IBM WorkPadT.TM., PalmPilot.TM., and the like), computer peripherals (such as printers, fax machines, and the like), handheld or palmtop computing devices, and the like. For convenience, these devices, as a class, are referred to herein as "pervasive computing" clients as they are devices that are designed to be connected to servers in a computer network and used for computing purposes regardless of their location.
Palmtop computers and the like are now being proposed as pervasive computing devices for use in an automobile. In-vehicle navigation systems, of course, are well-known. Representative systems are described in U.S. Pat. Nos.: 5,121,326, 5,191,532 and 5,792,109. U.S. Pat. No. 5,121,326 describes a navigation system that displays a general map of the driver's location. As the driver approaches an intersection, the display provides a detailed map of the intersection to provide further guidance to the driver. In U.S. Pat. No. 5,191,532, a navigation system is disclosed where driving directions can be provided even though the user's exact destination is not listed in the systems database. Certain geographic features such as cities and landmarks are used to approximate the destination for purposes of providing directions. In U.S. Pat. No. 5,729,109, the inventors provide a vehicle navigation system that uses speech generation to give spoken directions when the driver is approaching an intersection.
Although such existing in-vehicle navigation systems are useful for their intended purpose, the user interface for such devices is often fairly crude. Typically, the interface comprises a grid or map illustrating various roads, streets and intersections. Occasionally, these maps include other identifying information. Thus, while a user may be provided with some useful information from such displays, maps are often confusing, especially at some complex intersections. Moreover, these types of displays generally do not always provide sufficient information so as to enable a user to accurately determine if the vehicle has reached a given location represented on the map.
The present invention addresses the need to provide improved in-vehicle display of navigation information.